Some new aza thia crowns were prepared. A new diester was first prepared from the reaction of α,α′-bis(bromomethyl) benzene and methylthioglycolate. Aza crowns were synthesized from the reactions of this diester and diamines (ethylenediamine, 1,3-diaminopropane, 1,4-diaminobutane, 1,6-diaminohexane, and diethylenetriamine) in refluxing methanol (conventional heating) and under microwave (MW) irradiation. Based on the yields of aza crowns under these two conditions, MW irradiation is the better medium for these syntheses.